diff --git a/2018/src/day05.rs b/2018/src/day05.rs
index a573ee1..a5e506f 100644
--- a/2018/src/day05.rs
+++ b/2018/src/day05.rs
@@ -13,7 +13,7 @@ impl Day05 {
     fn reduce(mut data: Vec<u8>) -> usize {
         let mut dptr = 0;
         for iptr in 0..data.len() {
-            if dptr > 0 && (data[iptr].eq_ignore_ascii_case(&data[dptr - 1])) && data[iptr] != data[dptr - 1] {
+            if dptr > 0 && (data[iptr] ^ data[dptr - 1]) == 32 {
                 dptr -= 1;
             } else {
                 data[dptr] = data[iptr];